This invention relates to a system and method for emplacing a prosthesis and, more particularly, to a delivery catheter and method of use for placement within a corporeal lumen of a bifurcated graft having attachment systems.
It is well established that various fluid conducting body or corporeal lumens, such as veins and arteries, may deteriorate or suffer trauma so that repair is necessary. For example, various types of aneurysms or other deteriorative diseases may affect the ability of the lumen to conduct fluids and in turn may be life-threatening. In some cases, the damaged lumen is repairable only with the use of prosthesis such as an artificial vessel or graft.
For repair of vital vessels such as the aorta, surgical repair is significantly life-threatening. Surgical techniques known in the art involve major surgery in which a graft resembling the natural vessel is spliced into the diseased or obstructed section of the natural vessel. Known procedures include surgically bypassing the damaged or diseased portion of the vessel and inserting an artificial or donor graft attached to the native vessel by an anastomosis.
It is known within the art to provide a prosthesis for intraluminal repair of a vessel, such as an abdominal aorta having an aneurysm. The art has taught to provide a prosthesis positioned in a vessel then securing the prosthesis within the vessel with hooks or staples that are mechanically extended by the user. The early prior art devices were large in diameter, mechanically complex and in turn were susceptible to mechanical failure. Prior intraluminal grafting systems have embodied capsule catheters or balloon catheters, but were relatively stiff and of a relatively high profile. Similarly, the prior art systems were configured in such a way that the graft was relatively difficult to deploy in the correct position. In addition, prior systems having a capsule catheter assembly were usually configured such that the prosthesis was disposed within a unitary capsule.
In recent years, several devices have been developed to attempt to treat an aortic aneurysm through intraluminal repair. For example, U.S. Pat. No. 4,140,126 (Feb. 20, 1979), Choudhury, discloses a method and article for performing an aneurysm repair, wherein a prosthetic graft is utilized to replace the damaged segment of the blood vessel. A plurality of radially spaced anchoring pins are located adjacent each end of the graft and provide means for securing the graft to the wall of the vessel. An assembly is provided for moving the graft within the vessel and permanently anchoring the graft to the wall of the vessel.
U.S. Pat. No. 4,562,596 (Jan. 7, 1986), Kornberg, discloses a bifurcated aortic graft constructed for intraluminal insertion having a plurality of struts having angled hooks with barbs at their superior ends. An assembly for inserting the graft and implanting the hooks into the vessel lumen is also disclosed.
U.S. Pat. No. 4,787,899 (Nov. 29, 1988), Lazarus, discloses an intraluminal grafting system including a hollow graft having an attachment means located at one end of the graft. The system includes positioning means for moving the graft within the vessel, the positioning means having a capsule positioned at one end for covering the graft attachment means. The disclosed positioning means further includes an inflatable member for securing the attachment means within the lumen.
EPO Pub. No. 0 461 791 A1 (Dec. 18, 1991), Barone et al. discloses an aortic graft and apparatus for repairing an aneurysm. The disclosed system includes a tube graft secured within the aorta and an attachment means at each end of the graft. Intraluminal delivery is accomplished using a catheter having a balloon for expanding and securing the attachment means. The graft and attachment means are preferably enclosed by a sheath which covers the entire graft and attachment means.
U.S. Pat. No. 5,104,399 (Apr. 14, 1992), Lazarus, discloses an intraluminal grafting system including a tubular graft having attachment means positioned at both ends. The system includes a positioning means for transporting the graft through a vessel lumen and for deploying the graft within the lumen. The positioning means includes an inflatable member, a capsule and means for removing the graft from the capsule. The capsule is disclosed as a rigid cylindrical member covering the entire graft.
EPO Pub. No. 0 508 473 A2 (Oct. 14, 1992), Piplani et al., discloses an intraluminal grafting system including a catheter having a capsule formed of a helical wrap of metal ribbon. A bifurcated graft having attachment means is removably disposed within the capsule. Means is provided for moving the graft from the capsule, and an inflatable member is provided for securing the attachment means within a vessel lumen.
U.S. Pat. No. 5,256,150 (Oct. 26, 1993), Quiachon et al., discloses a large diameter sheath for use in introducing a catheter in the body of a patient. The sheath includes an flexible elongate sheath tube and a backflow adapter having a hemostatic valve secured to the proximal extremity of the sheath tube. The sheath may be used for introducing a large-diameter deployment catheter into a femoral artery of the patient.
U.S. Pat. No. 5,275,622 (Jan. 4, 1994), Lazarus et al., discloses an intraluminal grafting system including a catheter having a capsule formed of a helical wrap of metal ribbon. A tubular graft having attachment means at both ends is removably disposed within the capsule. Means is provided for moving the graft from the capsule, and an inflatable member is provided for securing the attachment means within a vessel lumen.
The foregoing patents and publications are incorporated herein by reference.
To provide consistency with the common usage of terms used in the medical surgical arts in the United States, the terms xe2x80x9cproximal, distal, inferior and superiorxe2x80x9d are used with a certain regularity within the present specification. Proximal refers to parts of the system, such as catheters, capsules and wires, which are closest to the user and closest to the portion of the system outside or exterior of the patient. Distal refers to the point farthest from the user and typically most interior to the corporeal lumen. The term superior refers to a location situated above and is used herein in description of the graft and attachment system. Inferior refers to the point situated below and again is used herein with the graft and attachment system. Thus, for applications in the abdominal aorta which use a femoral approach, the superior end of the graft resides within the most distal portion of the delivery catheter. Likewise, the inferior end of the graft resides within the proximal capsule which is on the most distal portion of the capsule catheter.
The term xe2x80x9cipsilateralxe2x80x9d typically refers to a vessel or part of a device which resides on the same side in which a device enters a lumen. For example, the ipsilateral tubular leg of a graft would be the tubular leg which resides in the iliac artery in which the capsule catheter enters the aorta. Similarly, the term xe2x80x9ccontralateralxe2x80x9d refers to a vessel or device residing on the opposite side of which the main device enters the aorta. For example, the contralateral attachment system resides in the contralateral iliac artery which is on the opposite side of the aorta from which the capsule catheter enters the aorta.
The present invention comprises an intraluminal delivery system for securing a prosthesis within or between vessels or corporeal lumens of an animal, such as a human. The preferred embodiment of the placement system is configured for introducing a graft into a corporeal lumen and positioning the graft in the area of the aortic bifurcation. The delivery system includes a balloon catheter, a capsule catheter and a capsule jacket.
In general, it is an object of the present invention to provide an intraluminal grafting system and method which overcome the disadvantages of the prior art systems. The present invention comprises a system and method for implanting a prosthesis utilizing a catheter assembly having a multiplicity of capsules. The prosthesis comprises a wye shaped bifurcated graft having a self-expanding attachment system at each of its three orifices. Each attachment system is contained within its own compact capsule during deployment. The graft and capsules are deployed by a catheter assembly designed for traversing the femoral, iliac and aortic vessels of a human anatomy.
The present system has several advantages over prior art systems. For example, the over the wire configuration of the balloon catheter enables traversing the aneurysm with a guide wire. Using a guide wire in this manner minimizes the risk of dislodging thrombus in the aneurysm, since the delivery system follows the guide wire, thereby preventing the distal tip from perforating the vessel wall. In addition, using a guide wire allows for traversing more difficult anatomy. Also, the guide wire lumen may function as a through lumen for real time angiograms during the emplacement procedure or to insert intravascular probes such as intravascular ultrasound systems.
As another advantage, the smaller diameter of the capsule assemblies of the present invention permit use of the invention in a larger patient population because the variances in iliac vessel diameter. Similarly, the smaller device diameter relative to the iliac diameter may allow for easier navigation inside the corporeal lumen especially with more difficult anatomy. Likewise, the two capsule segments of the present invention permit a wider range of graft lengths than available with a single capsule design. The single capsule systems also require capsules slightly longer than the graft, which imposes certain manufacturing and deployment problems. Moreover, the shorter capsule segments provide a more flexible device, thereby allowing traversing more difficult anatomy.
In the preferred embodiment, the balloon catheter and the capsule catheter include capsule assemblies for retaining the attachment systems, including a distal capsule assembly for retaining the superior attachment system and a proximal capsule assembly for retaining the ipsilateral attachment system. Also included within the delivery system is a contralateral capsule assembly for retaining the contralateral attachment system. The capsule assemblies are movable relative to each other to allow the graft to be emplaced at the desired location in the corporeal lumen.
Preferably, the delivery system includes a balloon catheter having a multilumen hollow tube or shaft having a proximal end provided with an assembly for accepting a guide wire and with an assembly for inflating a balloon or similar inflatable member. The balloon catheter shaft is of sufficient length that the proximal end remains exterior the corporeal lumen while the distal end of the balloon catheter shaft may be positioned proximate the portion of the corporeal lumen to be repaired. The balloon catheter further has an assembly for inflating and deflating the balloon. In addition, the balloon catheter is coupled to a control assembly and a distal capsule for retaining and releasing the superior end of the graft. In the preferred embodiment, the control assembly includes a control wire and handle mechanism which provides movement of the distal capsule relative to the balloon catheter shaft.
The delivery system also includes a capsule catheter shaped and sized for positioning within the corporeal lumen. The capsule catheter comprises a hollow tube or shaft slidably mounted on the balloon catheter shaft, having a proximal end exterior the corporeal lumen for manipulation by the user. The capsule catheter includes a proximal (ipsilateral) capsule secured to the distal end of the capsule catheter shaft for retaining the ipsilateral attachment system. The delivery system is configured to provide relative movement between the proximal capsule of the capsule catheter and the distal capsule of the balloon catheter for removing the graft from the capsule assemblies and for subsequently urging the attachment systems into engagement with the wall of the corporeal lumen.
The placement assembly further includes a capsule jacket for providing a smooth transition between the parts of the balloon catheter and capsule catheter. The capsule jacket comprises a singled walled jacket or sheath covering the length of the prosthesis and a double walled section over the capsule catheter tubular member. The capsule jacket is configured coaxially with the balloon catheter and capsule catheter, having a proximal end exterior the corporeal lumen for manipulation by the user. The distal end of the capsule jacket is single walled and flares outwardly to a size which is slidably retained over the distal capsule when the placement assembly in deployed into the corporeal lumen. The capsule jacket distal tip has a radiopaque marker to facilitate positioning using fluoroscopy or x-ray techniques.
The present invention includes a bifurcated prosthesis or bifurcated graft for intraluminal placement in a fluid conducting corporeal lumen. For most applications the prosthesis is a hollow bifurcated graft of preselected cross-section and length. The bifurcated graft is deformable to conform substantially to the interior surface of the corporeal lumen or other body part to be repaired. Preferably, the bifurcated graft is made of a material suitable for permanent placement in the body such as polytetraf luroethylene or a polyester. The tubular legs and/or the main tubular member of the graft may be crimped to resist kinking during and after deployment. During emplacement, the superior and inferior ends of the bifurcated graft are positioned within the corporeal lumen and the graft is configured such that the graft traverses the diseased or damaged portion of the vessel. To anchor the graft to the wall of the corporeal lumen, attachment systems are secured to the superior and inferior ends of the graft.
The attachment systems for the ipsilateral and contralateral legs of the bifurcated graft are somewhat smaller than the attachment system used for the main tubular member. The attachment systems for the legs are sized for emplacement within the iliac arteries. During deployment, the ipsilateral leg attachment system resides within the proximal capsule and the contralateral leg attachment system resides within the contralateral capsule. The smaller profile of the leg attachment systems allow them to fit within the smaller capsules which are configured to fit together within the capsule jacket. Having the leg attachment system within each capsule allows the attachment systems to be secured to the tubular legs prior to deployment. In addition, the encapsulation prevents entanglement of the attachment systems.
The preferred attachment system has wall engaging members. The wall engaging members of the superior attachment system are angled toward the inferior end of the graft. Similarly, the wall engaging members of the inferior attachment system are angled slightly toward the superior end of the graft. The wall engaging members of both attachment system have sharp tips for engaging the corporeal lumen wall. The preferred attachment system are formed into a V-shaped lattice or framework. The frame of the attachment system allows for elastic radial deformation resulting in a spring-like effect when a compressed attachment system is allowed to expand as the graft is released from the capsule assembly. In addition, radiopaque markers are secured to the longitudinal axis of the graft to facilitate orientation of the graft using fluoroscopy or x-ray techniques.
The delivery system further includes a contralateral capsule system for retaining the contralateral leg of the bifurcated graft. The contralateral capsule system comprises a retaining capsule, guiding tube and a pull wire. A segment of the contralateral capsule guiding tube is configured to reside in the capsule jacket, and the remainder of the guiding tube and pull wire extend out of the distal end of the capsule jacket assembly. In addition, a radiopaque marker coil on the guiding tube coincides with the distal capsule of the balloon catheter assembly to facilitate orientation, i.e. relative twist, between the contralateral capsule assembly and the ipsilateral capsule assembly.
During deployment, the contralateral capsule resides within the capsule jacket and adjacent to the proximal capsule assembly. The contralateral capsule guiding tube is traversed through the contralateral iliac artery in a conventional manner such that the contralateral leg of the bifurcated graft can be secured within the contralateral iliac artery. The contralateral capsule is configured to retain the inferior attachment system secured to the contralateral tubular leg. similarly, the contralateral guiding tube and capsule are configured such that the attachment system will remain within the capsule until such time when the clinician wishes to remove the capsule and free the attachment system within the contralateral iliac artery. The contralateral pull wire is disposed within the capsule jacket and along the distal capsule assembly and extends out the distal end of the capsule jacket.
Deployment of the graft comprises a series of steps which begins with introducing the main guide wire into the ipsilateral side of the corporeal lumen using well known surgical techniques. The contralateral guide wire and guiding tube are then inserted into the ipsilateral cutdown and are traversed through the contralateral cutdown using standard transfemoral techniques. Those techniques include use of a snare or guiding catheter traversed through the contralateral cutdown to assist in transferring the contralateral guide wire from the ipsilateral side of the corporeal lumen to the contralateral side. Next, as a single deployment catheter assembly, the balloon catheter, capsule catheter and capsule jacket are manipulated over the guide wire to position the capsules containing the bifurcated graft and attachment systems to a desired location within the corporeal lumen.
Once the graft is in the desired location, the capsule jacket is withdrawn to expose the entire graft and capsules containing the attachment systems. As the capsule jacket is retracted, tension is applied on the contralateral capsule assembly from the contralateral side of the corporeal lumen, thereby pulling the guiding tube out of the capsule jacket and into the contralateral lumen. The attachment systems are then simultaneously positioned at the desired locations. The distal capsule is then moved relative to the balloon catheter shaft and capsule catheter to expose the superior attachment system.
After the superior portion of the graft is removed from the distal capsule assembly, the inflatable member is moved to within the circumference of the superior attachment system and inflated to urge wall engaging members into the wall of the corporeal lumen. The contralateral capsule assembly is then withdrawn to expose the inferior attachment system of the contralateral tubular leg. An auxiliary balloon catheter is then positioned in the contralateral tubular leg to firmly secure the contralateral attachment system.
Once the contralateral tubular leg is secured, the proximal capsule assembly is withdrawn from the ipsilateral tubular leg, exposing the attachment system secured thereto. The deployment catheter is then moved to position the inflatable member proximate the ipsilateral inferior attachment system. The inflatable member is then expanded to seat the wall engaging members of the inferior attachment system. The deployment catheter is then removed from the corporeal lumen. An auxiliary balloon catheter is then positioned in the ipsilateral tubular leg to firmly secure the ipsilateral attachment system. All catheters and guide wires are then removed and the access to the corporeal lumens closed.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.